Solid-state drives (SSD) have been among the hottest hardware products for more than two years, with a good deal of uptake within the consumer PC, notebook and netbook markets in response to a precipitous drop in pricing in 2007 and 2008.

The fabricators of NAND flash chips, which are used to build SSDs, took a bath for more than a year beginning in 2007, even losing money on the products they sold. Pricing for NAND flash dropped as much as 60% year over year in 2007 and 2008.

"There was a definite oversupply of NAND. The problem was no one was making money in NAND or the memory industry at that point," says Steve Weinger, director of NAND flash marketing at Samsung, the industry's largest producer of NAND flash chips.

After the first quarter of 2009, however, SSD pricing leveled off and even increased as the economy forced NAND flash manufacturers to stop investing in new equipment and demand outstripped supply.

Research firm iSuppli Corp. says surging NAND flash prices last year hurt what was a booming SSD market. The price of a flash memory chips rose to $4.10 in the second quarter of last year, representing a $1.80, or 127%, increase from the final quarter of 2008.

Now, pricing is expected to flat-line until next year, when NAND flash chip fabricators will be able to reinvest their profits to ramp up production and begin selling higher-density products, industry experts say.

Where SSDs are used

SSDs were originally aimed at enterprise-class environments, with the highest quality single-level cell (SLC) NAND flash chips being used to ensure the highest performance and reliability. However, today, multi-level cell (MLC) NAND flash, which stores more than 1 bit of data per cell and therefore offers higher capacities, is approaching the same performance and reliability as SLC through the use of special firmware in the drive's controller.

The performance advantage for SSDs in the data center is tremendous. A single SSD, for example, can produce up to 16,000 input/output operations per second (IOPS). In comparison, a high-end 15,000-rpm Fibre Channel drive maxes out at 200 IOPS.

"You can replace 10, 20 -- I've even heard of 30 -- spinning disk drives, with a single SSD," says Dean Klein, vice president of memory system development at Micron Corp., a fabricator of NAND flash memory chips and SSDs.

But you pay a price for that performance. The cost of enterprise-class SSDs can be as low as $350, for a Micron realSSD C300 consumer drive that can be used in a server, or as high as $7,000, for an storage array-class drive, Klein says. It all depends on the features and performance you want.

For mainstream consumers, SSDs also vastly outpace hard disk drives when it comes to performance. In many cases, they have more than twice the I/Os per second, dramatically reducing computer boot-up times and application load times. And, because there are no moving parts -- no actuator arms or motors -- SSDs are more durable and therefore may be better choices for mobile devices.

But lately, with the increase and subsequent stabilization of SSD prices, the benefits of SSDs have largely been lost on consumers who are more attracted to a hard disk drive's higher capacity and lower price.

"The problem today is prices are prohibitively high for the average consumer," says Gartner analyst Joseph Unsworth. "When you consider a hard drive, you can get a terabyte for about $90. If you look at an SSD -- the Intel one I had with 160GB was $400. The point here is SSDs will never, ever be able to match hard disk drives on price per gigabyte."

Unsworth says that, for consumers, the decision to buy an SSD rather than a hard disk drive with greater capacity will come down to understanding and being able to justify the higher cost of an SSD. In other words, they must be able to appreciate "the performance, the boot time, the application acceleration, the reliability aspects and the slightly better power efficiency" of a solid-state drive, he says.

Online retail sales represent 40% of all SSD purchases today, Unsworth says. The people who are buying SSDs online are mostly tech savvy gamers or professional IT workers who shop at sites like Newegg.com, Amazon.com and Pricegrabber.com. The pricier drives give them superior performance for higher-end PCs and laptops.

The other market for SSDs is made up of equipment manufacturers; laptop and netbook vendors such as Lenovo, Dell and Hewlett-Packard are purchasing them for use in their consumer products. But sales of SSDs in that market are by no means booming.

"There have been 6.5 million consumer PC and notebook products sold with SSDs," Unsworth says. "That's far from widespread."

"The demand on the [equipment manufacturer] side is at present modest. It's behind everyone's forecast," Klein adds.

Last year, about 2.2 million SSDs sold in the netbook market, while 2.3 million were sold for use in notebooks and 316,000 were sold for servers, Gartner says. This year, those numbers will double in some cases.

Gartner predicts that in 2010, 3.6 million SSDs will be sold in the notebook market, 6.4 million in the desktop market and 819,000 in the server market.

Revenue is also expected to more than double for SSD vendors. In 2009, consumer and enterprise SSD sales reached $1.3 billion. This year, sales are expected to hit $2.9 billion, Unsworth says. "We expect revenue to double in the consumer space and triple in the enterprise space," he says.

Gregory Wong, an analyst at Forward Insights, believes that for PC, notebook and netbook manufacturers, SSD prices will drop from about $1.90 per gigabyte today to about $1.70. Online shoppers shouldn't see any marked decrease in pricing and can expect to continue to pay $3.00 to $3.30 per gigabyte on sites like Newegg.com.

Compared with hard drives, which cost about 30 cents per gigabyte, SSDs are 10 times more expensive, says Wong. But there's a crossover point where the base cost of a hard drive -- about $40 -- would buy an SSD with about 16GB of capacity. The lower-capacity SSDs could be used to run a PC's operating system and key applications, while files could be stored on a secondary internal or external hard disk drive.

A bright spot

The SSDs that are experiencing stronger sales today are low-capacity models that are purchased for use as "boot drives." Most such drives offer between 40GB and 64GB of capacity and cost about $100.

Last month, vendors such as Intel and OCZ began releasing lower-capacity SSDs, betting that enthusiasts would purchase them as boot drives. Kingston sells a 30GB SSD and Corsair and OCZ have 32GB products.

"It's really about performance," Unsworth says. "They add an external hard drive with half a terabyte, a terabyte or more that's used for backup or as their video library, their multimedia library, etc."

Driving prices down

For SSDs to become more affordable -- and for manufacturers to drop their prices -- NAND flash fabricators must cut their prices first.

"We've come through the worst downturn this industry has every seen," Klein says. "It hasn't really been until the last two quarters that we've been showing a recovery. People may object to the memory guys finally making some money, but frankly this is what allows us to build for their future. This is what allows us to start ramping up our Singapore [fabrication facility]."

Ultimately, only an increase in production will drive SSD prices down, and that isn't expected to begin until 2011, say Klein and others. Until that time, prices may dip somewhat as NAND flash manufacturers begin selling higher density flash chips based on lithography technologies that will drop below 30 nanometers in size.

Lithography is the process of creating cells and transistors in silicon, which are used to store bits of data. The smaller they are, the more data can be fit on a single NAND flash chip. At 25nm, the cells in silicon are 3,000 times thinner than a strand of human hair. But at that level, inter-cell electrical interference becomes a tougher obstacle to tackle.

Today, most manufacturers are using lithography in the 30nm to 40nm range. Micron, Intel and Samsung are using 34nm; Toshiba is using 32nm.

By moving to 25nm technology, manufacturers can double the number of bits stored on a wafer.

Micron and Intel have both announced that they'll be shipping 25nm products later this year. South Korea's Hynix Semiconductor plans to use 26nm manufacturing. Samsung plans a 27nm chip and Toshiba is moving to a 24nm chip.

And, here's the best news of all: Consumers will be the first to get the new SSD technology through the online retail channel, Unsworth says.

"If they're going to use that finer process ... for PC manufacturers, that requires a qualification time," Unsworth says. "They need to test them and make sure the SSDs [are durable], and make sure they don't get those calls from consumers, because that's who'll be calling [the PC and notebook] vendors."